1. Field of the Invention
The present invention relates to methods, apparatus, and systems for receiving a television signal, receiving and reproducing broadcast data, and, more particularly to methods, and apparatus, and systems for receiving television signals, appropriate for use in the signal processing of a broadcast data receiving television receiver which receives, displays, and reproduces data content, broadcast from a broadcasting station, which contains multiplexed characters, pictures, audio, and video.
2. Description of the Related Art
It is increasingly the case that terrestrial and satellite broadcasting stations have begun to broadcast television signals which include data signals. In this so-called data broadcasting, data from the station is superimposed on a carrier frequency and transmitted using a broadcasting radio wave. The data, received and stored in a receiver, is read into a personal computer or a dedicated terminal, and is then displayed using a widely available WWW (World Wide Web) browser software program.
In addition to personal computers and dedicated terminals, the data broadcasting service may be received by a television receiver, and new services making use of data broadcasting are expected. Specifically, by installing a receiver function for receiving broadcast data and a reproducing software program (a browser) in a television receiver itself, one can easily gain access to a wide range of information (independent data broadcasting) and enjoy service in which information linked with a television program is provided in text or pictures (program linked data broadcasting), even without a personal computer.
Standards covering such service in Japan include ARIB STD B24 standardized by the Association of Radio Industries and Businesses (ARIB). The construction of a television receiver for receiving satellite digital broadcast data will now be discussed referring to FIG. 25. The television receiver includes a tuner 251, a descrambler 252, a transport decoder 253, an audio decoder 254, a video decoder 255, a D/A converter 256, a loudspeaker 257, a CPU (Central Processing Unit) 258, a graphics generator 259, a moving-picture plane 260, a still-picture plane 261, a character/drawing plane 262, an image synthesizer 263, and a display unit 264.
To transmit data, a broadcasting station encodes program data of ordinary television programs, audio data, and data to be broadcast. These coded signals are first multiplexed and modulated, and then transmitted from an antenna. The signal transmitted from the antenna is delivered via a broadcasting satellite (BS) to a user terminal such as a personal computer, a dedicated terminal or a television receiver.
In operation, the tuner 251 in the television receiver selects a signal within a frequency band of a channel corresponding to a program selected by the user from among the received signals. The tuner 251 demodulates the input signal, subjects the demodulated signal to an error correction process, generates digital data in a form called a transport stream (TS), and outputs the digital data to the transport decoder 253 via the descrambler 252. The transport decoder 253 then extracts a packet of the digitized data corresponding to the program selected by the user.
Video data within the extracted packet is decoded by the video decoder 255, and is then sent to the moving-picture plane 260 within a graphics buffer. Audio data within the extracted packet is decoded by the audio decoder 254, and is output to the loudspeaker 257. The broadcast data in the extracted packet is sent to the CPU 258 and is decoded there. The decoded data is then stored in a data storage device.
When the content of broadcast data is displayed, the CPU 258 reads data stored in the data storage device and converts the data into an image of characters and drawings through the graphics generator 259, and then sends the image to the character/drawing plane 262 or the still-picture plane 261 in the graphics buffer. The character/drawing plane 262 mainly stores bit images of buttons serving as UI (User Interface) in data broadcasting, text, graphics, and pictures, and the still-picture plane 261 mainly stores bit images of photographic pictures. The image synthesizer 263 performs a synthesis process for synthesizing graphic data stored in the moving-picture plane 260, the character/drawing plane 262, and the still-picture plane 261 in the graphics buffer, and then outputs the synthesized data to the display unit 264.
Digital data is commonly broadcast using the DSM-CC data carousel defined in the ISO/IEC Standard 13818-6. The broadcast data, filtered through the transport decoder 253, includes text information, script information, picture information, and video and audio data, and the text information is described in the XML (extensible Markup Language) defined in the World Wide Web Consortium (W3C).
It has been recognized that convenience will be enhanced even further if the information delivered by data broadcasting service is displayed on a television screen and printed out for permanent record. To receive and print out the broadcast data, a personal computer receives the broadcast data at a broadcast data receiving board, stores the data and then prints out the data using a dedicated application program such as, for example, the program disclosed in Japanese Patent Laid-Open No. 11-313191, (Owada et al.) which teaches a system that delivers information of newspapers, magazines, and posters to a dedicated terminal.
The above-described conventional art has disadvantages. In the above-described method of storing and printing data using a personal computer, the personal computer needs to be prepared with a required software program installed therewithin. Also, a display content is printed out “as is,” in other words, the size and layout of characters are not optimized for printing.
For example, in the system proposed by Owada et al. in the above-cited Japanese Patent Laid-Open No. 11-313191, data is merely delivered to a dedicated printer device. Thus, the user is unable to enjoy videos of broadcast display data content or digital broadcasting using the same device.
In this way, the print content and the display content are independently handled in the conventional art, and the receiver is a separate unit. This independent treatment limits functionalities, because, for example, a content creator (a provider) cannot deliver the display content as a print content, or cannot mix a button or an icon for content printing in a broadcast display data content.
Also, since the display process and the printing process of the broadcast data content are independent from each other in the conventional art, the display process of the broadcast data content cannot be concurrently performed in parallel with the printing process.